Method of pneumatically edge wrapping a substrate

ABSTRACT

A controlled bladder wrap tool system and method are disclosed for edge wrapping a substrate in a tool with consistent process control. An expandable bladder or bladder diaphragm is mounted in the tool adjacent a cavity where it expands when inflated to fill the cavity and to bend, fold or wrap an overhanging portion of pliable material onto a substrate which are mounted in the tool.

CROSS REFERENCE TO A RELATED APPLICATION

This application is a divisional of C. P. Mitchell, entitled "ControlledBladder Wrap Tool System", Ser. No. 07/520,731, filed May 9, 1990 nowU.S. Pat. No. 5,139,604.

This invention relates to a contained and controlled bladder wrap toolsystem and more particularly to a tool system and to a method to edgewrap substrates automatically with consistent process control.

The invention is designed to be used with a full range of substratepanels and wrap vinyl, leather, cloth and any other pliable material inorder to form, as an example, headliners, instrument panels, boosterpanels, door panels, seat backs, console panels, header panels and otheredge wrap substrates for use in the automobile industry.

Such headliners, instrument panels and other panels of the typedescribed are now manufactured using mechanical devices and manualmethod steps for edge wrapping and gluing the overhanging portion of thevinyl wrap or leather cloth to the substrate. The requires considerablelabor costs, cycle times and also possible injuries to the person whomust utilize his or her hands in manipulating and bending the edge ofthe pliable material over the substrate repeatedly, day in and day out.This could cause injury to the person's hand resulting in compensationclaims against the employer.

It is therefore a feature of the present invention to use a containedand controlled bladder system to edge wrap pliable material over thesubstrate to form the required panel.

A further feature of the present invention is to provide a contained andcontrolled bladder system which is less costly than manual systems andmechanical systems now employed to make the required panels.

It is still a further feature of the present invention to provide acontrolled bladder wrap tool system which is designed to conform toalmost any shape of panel to be produced and further which does notrequire a dedicated machine.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a door for an automobile and showing adoor panel made according to the present invention.

FIG. 2 is a fragmentary plain view of the bladder wrap tool system, withparts broken away in order to expose the interior.

FIG. 3 is a vertical sectional view through a press, or other machinetool, fragmentarily shown, in which the bladder wrap tool system islocated between the upper and lower platens of the machine or press, andwith the bladder wrap tool system shown in an open position.

FIG. 4 is an elevational view, partly in section, with the bladder wraptool system in a closed position prior to the expansion of the bladderor bladder diaphragm.

FIG. 5 is a view similar to FIG. 4 but showing the bladder or bladderdiaphragm in an expanded position in order to force the overhangingportion of the pliable material against or over the edge of thesubstrate.

FIG. 6 is a view similar to FIGS. 4 and 5, with the bladder or bladderdiaphragm deactivated and with the edge of the pliable material bentover and secured to the substrate.

FIG. 7 is a view similar to FIG. 3 but showing the door panel in acompleted stage ready to be removed from the inner tool part.

FIG. 8 is a fragmentary view illustrating an air supply source and valvefor the bladder or bladder diaphragm of the bladder wrap tool system.

FIG. 9 shows a different contoured bladder wrap tool system for makinganother type of panel, with the bladder or bladder diaphragm shown in anon-expanded position.

FIG. 10 is a view of the modified contoured bladder wrap tool system ofFIG. 9 showing the bladder or bladder diaphragm in an expanded positionin order to bend over the edges of the pliable material on the substrateof the panel.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

Referring now to the drawings, FIG. 1 shows an automobile door 10 havinga door panel 12 of the type which can be manufactured according to themethod and apparatus of the present invention.

Specifically, the present invention relates to a controlled andcontained bladder wrap tool system which may be used with anon-dedicated machine or press 16, fragmentarily shown in FIG. 3, andcontaining the movable platen 18 and a stationary platen 20.

The controlled bladder wrap tool system 22 is designed to edge wrapsubstrates automatically with a pliable material and to do so withconsistent process control. The bladder tool system 22 includes an uppertool base 24 and a lower tool base 26. It further includes an inner toolpart 28 and a outer tool part 30 which cooperate, when in a closedposition, to form a cavity 31.

The inner tool part 28 is welded or otherwise secured to the lower toolbase 26. A passage 30 for vacuum is provided in the base 26 andintersects a passage 32 provided in the inner tool part 28. A supportsurface 34 is provided at the top of the inner tool part 28 forproviding a support surface for the general rigid substrate 36 and forthe overlying pliable material 38 which has an overhanging edge portion40.

The top support surface 34 is provided with a locator pin 42 which isreceived in a recess 44 provided in the inner tool support 28. Thelocator pin 42 is locked in place by means of a threaded set screw orpin 46. The substrate 36 and the pliable material 38 are provided withlocating openings in order to receive the locator pin 42 as illustratedin FIG. 3. This locates the substrate 36 and pliable material in therequired positions.

The upper tool part 30 is welded or otherwise secured to the upper toolbase 24. The outer tool part 30 is designed to carry the bladder orbladder diaphragm 50 and is shaped to receive the inner tool support 28as illustrated in FIG. 4 and thereby form the cavity 31. In analternative embodiment (not shown), the inner tool part 28 may bedesigned to carry the bladder or bladder diaphragm 50.

The outer tool part 30 is provided with a pair of slots 54 and 56 whichreceive flanges 58 and 60 respectively which are integral with thetubular bladder 50, as shown in FIG. 3. The outer tool part 30 is alsoprovided with four threaded openings 62 located around the periphery ofthe outer tool part 30. Corresponding openings are provided in theflanges 58, 60 of the bladder 50 in order to receive the threadedlocating elements 64. The locating elements 64 are screw threaded intothe outer tool part 30 and extend through the flanges 58, 60 of thebladder 50 to retain the bladder 50 in position with respect to theouter tool part 30.

The bladder or diaphragm 50 is designed to expand to four to six timesits size. The bladder 50 is made from silicone rubber and can withstandtemperatures up to 350 degrees F. The bladder 50, as an example, has awall thickness of 0.062 inches plus or minus 0.005 inch. It has a heightas viewed in FIG. 3 of two inches and is thus referred to as a two inchbladder with an expansion ratio of four or six to one. The legs orflanges 58, 60 provided on the bladder 50 are approximately 1.12 inchesin length.

The bladder 50 is connected to an air supply system as shown in FIG. 8.Bladder 50 is connected to a nozzle 68 by a fastener band 70. The nozzle68 is connected by tubing 72 and a valve 74 to the air supply system,not shown.

The bladder 50 is located adjacent to or in the cavity 31 formed by theinner and outer tool parts 28 and 30 when in a closed position as shownin FIG. 4, 5 and 6. The air from the air supply source expands thebladder 50 which will take the shape or the contour of the cavity 31.The cavity 31 can vary in size and shape in order to make the requiredpanel.

In FIGS. 3 and 4, the substrate 36 has an overhanging portion 37extending into cavity 31. Portion 37 is provided with a hump or curvededge 39 around which the overhanging portion 40 of the pliable materialis wrapped. Tubular bladder 50 surrounds and abuts overhanging portion40 of the pliable material 38 when the tool parts are closed, as shownin FIG. 4. The upper tool base 24 has a surface 25 parallel to andspaced from the support surface 34. Grooves or indentations 27 areprovided in surface 25 for receiving the hump or curved edge 39 of thesubstrate 36 when the tool parts are closed as shown in FIGS. 4 and 5.

Prior to placing the pliable material on the substrate carried by thesupport surface, adhesive is applied to the overhanging portion 40 ofthe pliable material so that it will stick or be secured to thesubstrate edge portion 37 when moved into contact therewith by theexpanding bladder 50 as shown in FIG. 5. The bladder or diaphragm 50expands and completely fills the cavity 31. The bladder 50 is containedby the inner and outer tool parts and take the shape or contour of thecavity 31. Thus, each different part to be manufactured will have innerand outer tool parts of different configurations. The bladder 50, whenexpanded, engages the overhanging portion of the pliable material, andbends and forces it into adhesive engagement with the underside of thesubstrate portion 37 as shown in FIG. 5.

With respect to the described controlled bladder wrap tool system,Applicant discloses a method of pneumatically edge wrapping a portion 40of a sheet of pliable material 38 over a portion 37 of the substrate 36.Such method is practiced by using a tool system having an inner toolpart 28 of a predetermined configuration and an outer tool part 30 of apredetermined configuration which is generally hollow and is adapted toreceive the inner tool part 28 so that they may cooperate to define acavity 31 in which is located the expandable bladder diaphragm 50.

The method steps include mounting a substrate 36 on the support surface34 of the inner tool part 28. The substrate is mounted so that a portion37 of the substrate 36 overhangs the support surface 34.

A further method step includes mounting a sheet of pliable material onthe support surface 34 overlying the substrate 36, with a portion 40 ofthe sheet of pliable material extending into the cavity 31 beyond theoverhanging portion 37 of the substrate 36.

After the inner and outer tool parts are moved to a closed position bythe press 16, the bladder or bladder diaphragm 50 is pneumaticallyinflated within the cavity 31 and a portion of the bladder diaphragm 50is urged against the portion 40 of the pliable material 38 in order towrap or bend it over the overhanging edge portion 37 of the substrate36. After the substrate 36 is edge wrapped as just described, the pressis opened, the inner and outer tool parts are separated and the productis removed from the tool parts.

Another method step includes the step of placing an adhesive on theportion of the pliable material before mounting the sheet of pliablematerial on the support surface 34.

The method of pneumatically edge wrapping a substrate further includesthe step of applying a vacuum to the tool system prior to inflating thebladder diaphragm.

The method of pneumatically edge wrapping a substrate may also includethe step of positively locating the substrate 36 and the sheet ofpliable material 38 on the support surface 34 prior to the inflation ofthe bladder diaphragm 50. The invention also contemplates the step ofsecuring the inner and outer tool parts to the upper and lower toolbases respectively so that the control bladder wrap tool system may beused in a non-dedicated machine tool or press.

The function of the bladder wrap tool system is to edge wrap substratesautomatically with consistent process control. It can be used with afull range of substrate panels and vinyl wrap, leather, cloth and otherpliable material. It will generally wrap 90 percent to 100 percent ofany given substrate. As indicated previously, each tool system needs tobe designed for the given substrate.

The basic components of the edge wrap tool system can be made from anycommon tooling material such as steel, aluminum, plastic or wood. Thechoice of tool materials is based upon design and function of the tool,i.e. prototype or production, cycle life expectancy and processprocedures.

It should also be understood that the controlled bladder wrap toolsystem of the present invention may be utilized by loading the toolsystem with a substrate having a pre-applied wrap material or by loadingthe tool with a substrate and with a wrap material as described herein.In either instance, the tool system is closed and vacuum is applied tothe bladder containment tool. Thereafter, air is directed to the bladderor bladder diaphragm 50 in order to expand the bladder, which willassume the shape of the cavity 31, and force the overhanging portion ofthe wrap material against the substrate. As indicated, the bladder 50inflates and conforms to the containment contour of the cavity 31. Asthe bladder 50 expands and assumes the contour of the cavity 31, thewrap material will wrap or bend around the substrate and is securedthereto by the adhesive.

FIG. 9 and 10 illustrates a modified control bladder wrap tool system 80having an inner tool part 82 and an outer tool part 84 to which isappropriately connected the expandable or inflatable bladder or bladderdiaphragm 86. When the inner and outer tool parts 82 and 84 areseparated, a substrate 88 having, on one side thereof, pliable material90 with an overhanging edge portion 92 is placed in the apparatus 80 asshown in FIG. 9. The overhanging edge portion 92 engaged the bladder 86.A cavity 94 is located between the inner tool part 82 and the outer toolpart 90 when the inner and outer tool parts are closed as shown in FIG.9. Prior to closing the tool, adhesive is applied to the overhangingedge portion 92 of the pliable material 90. Thereafter, after theclosing of the tool parts by the press, the bladder or expandablediaphragm 86 is inflated to four or five times its size so as tocompletely assume the contour configuration of the cavity 94 and toforce, bend and thereafter secure the overhanging edge portion 92 of thepliable material 90 to the edge portion of the substrate 88 asillustrated in FIG. 10. The air pressure is maintained for a period oftime depending on the curing rate of the adhesive in order to secure thepliable material to the substrate 88.

It should be appreciated that the controlled bladder wrapped tool systemmay contain any number of bladders or bladder diaphragms in one tool. Asan example, eight to ten bladders could be used in one tool andthereafter the bladders would be inflated in sequence to perform thedesired bending and folding functions.

The controlled bladder wrapped tool system may be used with a standardpress. Thus requirement for a dedicated press have been eliminated bythe present invention.

Preferred embodiments of the present invention have been disclosed;however, a worker of ordinary skill in the art would realize thatcertain modifications including the use of a plurality of bladders wouldbe considered within the scope of this invention, and thus the followingclaims should be referred to to determine the scope and content of thepresent invention.

What I claim is:
 1. The method of pneumatically edge wrapping a portionof a sheet of pliable material over an edge portion of a substrate byusing a tool system having open and closed positions, with the toolsystem having an inner tool part provided with a support surface and anouter tool part which cooperates with the inner tool part and thesupport surface thereof when in the closed position to define a closedcavity in which is fixedly located an expandable tubular bladderdiaphragm comprising the steps of:(a) mounting a substrate on thesupport surface of the inner tool part while the tool system is in theopen position, with a portion of the substrate overhanging the supportsurface and extending into the closed cavity when the inner and outertool parts are in the closed position, the overhanging substrate portionhaving upper and lower surfaces; (b) mounting a sheet of pliablematerial on the support surface overlying one side of the substrateincluding the upper surface of the overhanging substrate portion, with aportion of the sheet of pliable material extending into said cavitybeyond the overhanging portion of the substrate when the closed cavityis formed; (c) moving the inner and outer tool parts together to aclosed position to form the closed cavity, with the expandable tubularbladder diaphragm surrounding and abutting the overhanging portion ofthe sheet of pliable material, wherein the tubular bladder diaphragm hasa pair of flanges which are received in retaining slots located in oneof the inner and outer tool parts, and a series of threaded retainingelements carried by the last mentioned one tool part and extendingthrough said flanges and slots to hold the tubular bladder diaphragm inplace; (d) pneumatically inflating the tubular bladder diaphragm withinthe closed cavity to urge the diaphragm against said overhanging portionof the pliable material resulting in the expansion of the bladderdiaphragm to occupy the closed cavity and to wrap the overhangingportion of the pliable material over the overhanging portion of thesubstrate against the lower surface of the overhanging substrateportion, wherein the tubular bladder diaphragm is connected to a sourceof air via a passage which extends from said source through the inner orouter tool part to which the tubular bladder diaphragm is connected; (e)opening the inner and outer tool parts to expose the edge wrappedsurface mounted on the support surface of the inner tool part; and (f)removing the edge wrapped substrate from the inner tool part.
 2. Themethod of pneumatically edge wrapping a substrate as defined in claim 1,including the step of placing an adhesive on the portion of the pliablematerial before mounting the sheet of pliable material on the supportsurface.
 3. The method of pneumatically edge wrapping a substrate asdefined in claim 1, including the step of applying vacuum to the toolsystem prior to inflating the bladder diaphragm.
 4. The method ofpneumatically edge wrapping a substrate as defined in claim 1, includingthe step of positively locating the substrate and sheet of pliablematerial on the support surface prior to the inflation of the bladderdiaphragm wherein the outer tool part is secured to an upper tool baseand said locating step is performed by a locating pin carried by thesupport surface of the inner tool part which locating pin extendsthrough openings provided in the substrate and in the pliable material,the locating pin being received in an opening provided in said uppertool base when the tool parts are in the closed position.
 5. The methodof pneumatically edge wrapping a substrate as defined in claim 1,including the step of securing respectively the inner and outer toolparts to upper and lower tool bases.